Photoenlarger



Oct. 17, 1939.

D. FRIEDMAN PHOTO ENLARGER Filed June 5, 1937 4- Sheets-Sheet 1 Oct. 17, 193% D. FRIEDM N 2,176,625

PHOTOENLARGER Filed June 5, 1957 4 sheets sheet 2 ldL D. FRIEDMAN Oct. 17, 1939.

PHOTOENLARGER 4 Sheets-Sheet 3 Filed June 5, 1957 Wtouwq f w a Oct, 17, 1939.

D. FRIEDMAN PHOTOENLARGER Filed June 5, 1937 4 Sheets-Sheet 4 Patented Oct. '17, 1939 v UNITED STATES PATENT OFFICE 13 Claims.

This invention relates to photoenlargers, and more particularly to such devices capable of use for a variety of related purposes, including use as a safety light for dark room purposes, etc.

In the prior art, a large number of devices have been suggested for use as photoenlargers, etc. They are of relatively complex structure and resultant high cost in construction, since to perform the various functions required of such devices has necessitated elaborate "structures and complicated mechanisms for the utilization for the desired functions.

Among the objects of the-present invention is the production of photoenlargers of relatively simple construction, and consequent low cost of manufacture, enabling all of the necessary functions of such devices to be performed by a unitary simple structure.

Other objects include structures of the character set forth above, and means for converting them into safety lamps for dark room purposes.

Many other objects and advantages will appear from the more detailed description set forth below, it being understood, however, that this more detailed description is given by way of illustration and explanation only, and not by way of limitation, since various changes therein may be made by those skilled in the art without departing from the scope and spirit" of the present invention.

In accordance with that more detailed description, there is disclosed in the accompanying drawings, in

Figure 1, a side elevation of a photoenlarger produced in accordance with the present invention; in

Figure 2, a front elevation of the photoenlarger of Figure l; in a Figure 3, a sectional view taken on line 3-3 of Figure l, the parts being shown on an enlarged scale as compared with Figure 1; in

Figure 4, a sectional view taken 'on line l4 of Figure 3; in

Figure 5, a transverse sectional view taken on line 55 of Figure 4; in

Figure 6, a detail sectional view taken on line 6-6 of Figure 1 and .drawn on an enlarged scale;

Figure 7, a sectional view taken on line 'I'I of Figure 1; in

Figure 8, a detail bottom plan view of a mask to be used in connection with the photoenlarger of Figure 1; in p Figure 9, a fragmentary bottom plan of the projector unit; in

Figure 10, a sectional view taken on line Il 0 of Figure 1; in

. Figure 11, a fragmentary sectional view of a modified form of masking device; and in Figure 12, a sectional view taken on line l2-l2 of Figure 11.

A consideration of the device shown in the drawings and illustrating a photoenlarger" produced in accordance with the present invention shows that it is concerned with a relatively simple l0 unitary structure, enabling all of the desired functions to be performed by a device of this character, while utilizing structural features of relatively simple and inexpensive character.

- For this purpose, a projection unit is desirably l5 employed which is mounted for movement in a variety of planes, including, for example, movement on a horizontal axis, on a vertically adjustable support, and rotary movement about a fixed point on the base. These several movements enable the projector unit to be utilized effectively, and adjusted to suit particular conditions.

Referring more particularly to the projector unit shown in the drawings, a body member 20, desirably formed of a cylindrical casing is provided with a head portion 2| of dome-shaped character hingedly carried on the casing 20. The body member 20 carries a lateral bracket 22, provided with a trunnion 23 serving as the horizontal axis about which the projector unit may rotate. For this purpose, the trunnion 23 is journalled in a bearing 24, carried on a support member 25. As shown, the outer end of the trunnion 23 may be threaded for reception of a nut 23 enabling the projector unit to be'fixed in any desired position when rotated about the horizontal axis formed by the trunnion 23.

The dome-shaped head 2| may be mounted in any desired way on the body or casing 20, and 40 for this purpose ears 26, 26 may be formed on the bracket 22, between which cars 26 the hinged arm 21, carried on the dome-shaped head 2|, is pivotally mounted.

The upper portion of the casing 20 may be flanged or offset to provide a seat 28, the outer portion of the offset or flange being enlarged to form the head or rim 29. Desirably, as shown in Figure 9 of the drawings, the enlarged bead or rim 29 extends about the upper perimetric edge of the body member or casing 20 for only a portion of the circumference, leaving spaced portions 23'. These unguarded portions 29', 29' communicate with a channel as described below, 55

through which a transparency, such as a picture film, may be passed.

A mask 30 (see Figure 8) of a contour corresponding with that of the casing or body member 20 is adapted to seat on the offset portion 28, and this mask 30 is provided with a central opening 3| desirably square in character. The opening 3| in the mask 30 may take different contours or shapes, and a series of masks of varying types of openings may be utilized. The mask 30 carries a frame 32 on the bottom of the mask, and is normally pressed against the bottom of the mask 30 by a spring or equivalent device 33, shown as a coiled spring carried on the pintle of the hinge. The frame 32 corresponds in character with the opening 3| in the mask 30. Desirably the lower surface of the mask and the upper surface of the frame are covered with material, such as felt or the like, to prevent injury to a film 34 held between the frame member 32 and the mask 30. A set screw 35 desirably carried on the frame on the side opposite that of the hinged joint permits the frame to be spaced from the bottom of the mask 30, enabling the film 34 or other transparency to be moved to the desired adjusted position without removal of the mask 30.

Desirably, a disc of plain glass 36 provided with a rubber covered edge 36 is mounted above the mask, and seats between the latter and the lower edge of the dome-shaped head 2|, the rubber covered edge 36' serving to prevent the passage of light at this point.

A condenser lens 31, desirably held by a split spring ring 38 in position on the lower end of the dome-shaped head 2|, is provided, a recess being formed in the inner wall of the domeshaped head 2| for this purpose. The upper surface of the lens 3! may desirably be frosted to cause better diffusion of the light passing therethrough.

Any source of light may be employed, but desirably an electric bulb or incandescent lamp 39 is mounted in a socket 39 carried in the upper portion of the dome-shaped head 2|. For this purpose, desirably the dome-shaped head 2| is provided with a cylindrical extension 40, in which the socket 39 is mounted, and from which the connecting electric cords or wires may be carried through the standard 62, as shown in Figure 1. The incandescent bulb 39 desirably has its lower end shielded by a 'cap 4| to prevent light from passing directly from the incandescent bulb downward, so that light which reaches the lens 31 is that obtained by reflection from the inner walls of the dome-shaped head member 2|. The inner surface of the domeshaped head member is desirably painted white, as with a white casein paint, to assist in the even distribution of the light reflected therefrom to and through the condenser lens 37!.

Means are desirably provided for cooling the dome-shaped head member, and preventing the building up of heat in this unit due to the incandescent bulb 39. For this purpose, the eX- tension 45 on the dome-shaped head member 23 may desirably be provided with lateral annular fins and in addition the extension 45 desirably is provided with a series of slots 43, providing a passage for heated air from the interior of the dome-shaped head member 2| to the external atmosphere. The fins 42 not only assist in dissipating the heat, but also serve to prevent the passage of light from the interior of the domeshaped member, and for this purpose, the surfaces of the fins 42 may desirably be painted black.

A shield or bafile 44 carried on the socket 39 is desirably provided for preventing light from the lamp or bulb 39 reaching the extension 40. The under surface of this shield 44 may desirably be given a white or light-colored surface, as by .means of white casein paint, to assist in reflection of light.

The dome-shaped head member 2| is desirably provided with ports or openings 45, 45, placed along the lower portion of the walls of the domeshaped head member 2|, and desirably at a point below the bulb 39, or the exposed portion thereof. These ports 45, 45 having cylindrical extensions 45', 45 with fins and slots analogous to those described above in connection with the cylindrical extension 40. In view of the position of the ports or openings 45, 45, these ports'remain substantially cool at all times, and air entering through these ports circulates through the dome-shaped head member becoming heated by the lamp or bulb 39, and passing upwardly out of the slots 43 in the cylindrical extension 40.

The dome-shaped head member 2| hingedly mounted on the body or cylindrical casing 20 is provided with means for holding it in closed position on said body or casing 25. And for this purpose, a projecting arm 46 is provided carrying a pointed set screw 46, adapted to engage the head or rim 29, and to hold the domeshaped head member 2| in closed position on the body portion or casing 20.

A lens carrier 41 is provided, and may take any desired form, that shown being cup-shaped and mounted for slidable movement along the inner walls of the body or casing 20. The lens carrier 4'! has a web 4'! constituting a base member provided with a threaded opening for reception of a conventional lens 48. As in such conventional lens systems, an iris diaphragm is provided, which may be regulated by means of thelever 49 engaging a serrated arcuate plate 50.

The lens carrier 41, as is noted above, is desirably mounted for movement within the body or casing 20. And for this purposefit may be provided with an extension (see Figure 3) engaging with a screw 52, desirably provided with a fast thread (about two turns per inch), the screw being carried in a housing 52 carried on the body or casing 20, and adjustable by means of the knurled button 53 keyed to the screw 52.

In order to utilize the projector unit as a safety lamp for dark room purposes, means may be provided for preventing light from passing through the lens 48. This may be accomplished by mounting a shield or mask for the lens 48 on the web bottom 47 of the lens carrier 41. Thus a shaft 55 (see Figure 3) may be carried through the web 41" of the lens carrier 41 carrying a frame 54 at the upper end of the shaft 55, the frame 54 having a red glass mounted therein as shown at 54'. Movement of the shaft 55 carries the mask 54 over the lens 48 and interposes the ruby glass 54 between the source of light 39 and the lens 48, thereby preventing white light from entering the lens. Desirably in utilizing the device as a safety lamp, the inner walls or surfaces of the body or casing 20 and of the lens carrier 47 are darkened or blackened as by means of paint or other coating.-

Instead of utilizing the mask 54, 54' for converting the projector into a safety lamp, other means may be utilized, a modification for that purpose being shown particularly in Figures 11 and 12. In the modification there shown, the cap or shield 4| carried on the lower end of the bulb 39 is desirably provided with an upper marginal flange 56. A cylinder 51 of red glass or of metal where all light is to be excluded, is carried by a cup-shaped member 58 secured to the lower ends of the rods 58', the latter being slidable through openings in the cylindrical extension 40 carried on the dome-shaped head member 2|. The outer and upper ends of the rods 58' are connected together as by means of a bolt within the hollow bail 59, a small spring carried on said bolt and within the hollow bail normally spreading the upper ends of the rods 58' and urging them apart, so that they frictionally engage the openings, the walls of the openings through which they pass in the cylindrical ex-' tension 40, and maintain the glass or metal cylinder 51 in any desired position. By making the flange 56 sufiiciently extensive, as shown in Figure 11, it is not necessary to bring the cylinder 51 into actual contact with the flange 56, and some space may thus be left between the end of the cylinder 51 and the flange 56 to permit air to circulate between the bulb 39 and the cylinder 51, the extended flange preventing light from the bulb reaching the inner surfaces of the domeshaped head member 2|.

The support 25 on which the projector unit is mounted, is carried on arms supporting it above the base. For this purpose parallel arms 60 are pivotally connected to the sleeve 6|. The sleeve 6| is slidably mounted on the standard 62, the standard 62 being mounted on the base B. 'In order to retain the parts in adjusted position, one of the arms 60 is provided with a clamping element '63, which in locked. position holds the support 25 in fixed relation with respect to the arms 60. The sleeve 6| comprises a split ring, as shown in Figure 6, held together by means of the screw 64. A gear 65 operated by the handle 66 moves in the rack 61 to enable the sleeve to be raised or lowered on the standard 62. While the device may be supplied with the structural features set forth above with respect to the support 25, the arms 69, and the sleeve 6|, these features are not essential and may be eliminated, the projector unit being movable vertically to and from the base B by means of the gear and rack arrangement carried on the sleeve 6|.

The operation of the device will be apparent from the structural features set forth above. Assuming that the enlarger has been used for its usual function, a film or transparency having been placed in position adjacent the mask 30,

and the enlargement made, the screw 46 may be loosened to permit the dome-shaped head member 2| to be raised and swung rearwardly. The glass 36 and the mask 30 are then removed. The frame 32 may then be moved on its pivot and the film or transparency 34 removed, and another inserted. The mask is then returned to its position seated on the ofiset portion 28, the glass 36 replaced above the mask, and the dome-shaped head member closed and locked in position by means of the screw 46'.

With no se sitized paper on.the base B, the electric switch to the bulb or lamp 39 may be closed, the clamping nut 64 released and the support 25 raised or lowered until the projected image on the base is of the approximate size desired. Final exact adjustment may then be made by means of the gear and rack mechanism '65 and 61. The lens 48 is then focused by means of the screw 52 and knob 53, and the shaft 55 rotated to bring the'glass shield 54 over the lens opening of the lens 48. In this condition, the

photoenlarger acts as a safety lamp. The sensitized paper may then be placed on the base, after 1 desired, the shield 54, 54' is again moved into position to produce the safety lamp device, and the exposed sensitized paper removed.

When a transparency in the form of a continuous strip of film is being used, the screw 35 may be used to space the frame 32 sufficiently from the mask 30 to prevent the strip of film from being irnmovably clamped against the mask, enabling the film to be moved even after the dome is in closed position, the strip of film in such case passing between the frame 32 and the mask 30, and through the openings 26' formed in the discontinuous bead 29.

A consideration of the structure and functions of the device as given above illustrates that a number of desirable effects and results can be secured. For example, in view of the mounting shown, the photoenlarger can be moved through a 'number of different planes, and such movements can be simultaneous or successive as desired, and movement in any selected group or individual planes can be utilized. Thus a rotary movement of the standard 62 on the base B in the socket 68 enables the photoenlarger to be swung in a radial direction. The sleeve 6| can be raised or lowered on the standard 62 to effect vertical movement of the projector with respect to the base 13. Release of the clamping element 63 enables movement of the parallel arms 60 to vary the position of the photoenlarger with respect to both the standard 62 and the distance therefrom, as well as with respect to the base B and the distance therefrom. Furthermore, the photoenlarger may be moved about the trunnion 23 and locked in any position with respect thereto. These several movements which can be utilized individually or in combination enable any desired positioning of the photoenlarger to be made radially, horizontally, or vertically.

Due to the various movements thus possible, the image obtained from the original transparency may be diametrally increased or decreased as desired, while still permitting sharp focussing adjustment with any desired size of image. In this same way, the perspective of the projected image may be altered to produce desired results, such as creating a parallel illusion of convergent or divergent perspective.

While these and many other functions and results may be secured, it will be seen that the photoenlarger is so assembled that it may be readily disassembled and reconstructed rapidly without the aid of tools, so that the device becomes readily portable. On reassembly the parts are such that no difhoulty is experienced, and assured relation of the parts in the desired structure is obtainable.

Having thus set forth my invention, I claim:

In a photoenlarger, a body member, a head member mounted on said body member and pivotable relative thereto, a light source carried in said head member, a seat carried on the upper portion of said body member adjacent said head member, a transparency receiver positioned on said seat contiguous to said head member, a lens mounted on said body member for reception of light projected from said light source through said transparency holder, means for varying the distance of said lens from said transparency 75 holder, and means for masking light passing from the light source to said lens, said masking means comprising a light-modifying sleeve adjustably supported on said head member for movement with respect to the light source to modify the light transmitted therefrom through the transparency.

2. A photographic enlarging apparatus comprising a vertical support rotatably mounted on its longitudinal axis, means mounted for adjustable movement in a vertical plane upon the said vertical support, lever means pivotally aflixed to the said vertical means at one end for movement relative thereto, a second support pivotally affixed to the other end of the said lever means for movement relative to the said lever means, and a projector means attached to the said second support so as to be rotatable about its horizontal axis.

3. A photographic enlarging apparatus comprising a vertical support, means mounted for movement in a vertical plane upon the said vertical support, lever means pivotally affixed to the said vertical means at one end for movement relative thereto, a second support pivotally affixed to the other end of the said lever means for radial movement relative to the said lever means, and a photographic projector means mounted on the said second support for rotation about a horizontal axis.

4. A photographic enlarging apparatus comprising a vertical support rotatably mounted on its longitudinal axis, means mounted for movement in a vertical plane upon the said vertical support, spaced parallel lever arms pivotally affixed to the said vertical means at one end for movement relative thereto, a second support pivotally affixed to the other ends of the said spaced parallel lever arms for movement relative to the said arms, and a projector means attached to the said second support so as to be rotatable about its horizontal axis.

5. A photographic enlarging apparatus comprising a vertical support, means mounted for movement in a vertical plane upon the said vertical support, lever means pivotally afiixed to the said vertical means at one end for movement relative thereto, a second support pivotally affixed to the other end of the said lever means for movement relative to the said lever means, a bearing means afiixed to the said second support providing a horizontal axis of rotation, and a photographic projection means ailixed to the said second support and mounted for rotation on the said bearing means about the said horizontal axis.

6. A photographic enlarging apparatus comprising a vertical support rotatably mounted on its longitudinal axis, means mounted for movement in a vertical plane upon the said vertical support, spaced parallel lever arms pivotally affixed to the said vertical means at one end for movement relative thereto, a second support pivotally affixed to the other ends of the said spaced parallel lever arms for movement relative the said arms, a bearing means afiixed to the said second support providing a horizontal axis of rotation, and a photographic projection means afiixed to the said second support and mounted for rotation on the said bearing means about the said horizontal axis.

7. In a photoenlarger, a base, a standard mounted on said base and rotatable about its longitudinal axis, a sleeve slidably carried on said standard, means for locking the sleeve into position on said standard, spaced parallel arms pivoted at one end of each arm on said sleeve, a photoenlarger mounted for rotation about a horizontal axis and pivotally affixed to the other ends of the said arms, whereby the said enlarger is rotatable about a vertical and horizontal axis and movable in horizontal and vertical parallel planes, and a clamp for locking said photoenlarger against movement with respect to said arms.

8. The combination as in claim 5 in which the said projector means comprises an upper and lower portion, the said upper portion being pivotally mounted relative to the said lower portion on the said second support.

9. The combination as in claim 5 in which the said projector means comprises a head member and a body member, a transparency support provided at the upper portion of the body member adjacent the said head member, the said head member being pivotally mounted relative to the said body member on the said second support at the line of transparency support.

10. The combination as in claim 5 wherein the means mounted for movement in a vertical plane comprises a split sleeve, and wherein the movement is actuated by gear and rack means.

11. In a photoenlarger a substantially rigid body member, a head member mounted on said body member, a light source carried in said head member, a seat carried on the upper portion of said body member adjacent said head member, the said head member being pivotally mounted along the line of said seat relative to said body member, a transparency member positioned on said seat adjacent to said head member, means for circulating air from the bottom of the said head member through a top area thereof, and a light modifying sleeve adjustably supported on said head member for movement with respect to the light source to modify the light transmitted therefrom through the transparency.

12. The combination as in claim 1 including means adapted to circulate cooling air from approximate the bottom to the top of the said head member and laterally of said light source and masking means.

13. In a photoenlarger a substantially rigid body member, a head member mounted on said body member, a light source carried in said head member, a seat carried on the upper portion of said body member adjacent said head member, the said head member being pivotally mounted along the line of said seat relative to said body member, a transparency member positioned on said seat adjacent to said head member, and a light modifying sleeve adjustably supported on said head member for movement with respect to the light source to modify the light transmitted therefrom through the transparency.

DAVID FRIEDMAN. 

